Future by design: a framework for introducing radical change in urban rail systems

Urban mobility is increasingly becoming accepted as a basic human need, when socio-economic opportunities depend on the ability to reach places within acceptable times. On the other hand, the emergence of megalopoleis as dominant features of the global landscape has been increasing commuting effort to unprecedented levels. These ever-larger urban areas allowed by the dominance of the automobile and their associated travel distances highlight important shortcomings in the operation of mass transport systems. Public transport users in megalopoleis spend up to two times longer than drivers for covering similar distances, exacerbating important social and economic inequalities and reinforcing the preference for private modes. However, even though there is an assumption that the problem can be easily overcome by increasing the speed of transport systems, advocates of this approach overlook important utility trade-offs that arise from the conflict between greater vehicle speeds and the additional time required to access the services. The first original aspect of the thesis is the deeper understanding of the inherent limitations of paradoxes in urban rail systems. For instance, metro systems are inherently constrained by a paradox between access and in-vehicle speeds, which prevents them from offering sufficient door-to-door speeds to cover long distances within acceptable travel times. It becomes clear that these systemic limitations can only be solved by radical innovation, especially in cases where the systems environment is rapidly changing. The first part of the research comprises a literature review on the foundations of engineering to understand how to achieve radical change in socio-technical systems. This in turn leads to the second original aspect of the thesis: a novel heuristic framework that combines the backcasting method with a system engineering approach to develop innovative solutions that are equally robust and resilient in face of the uncertainty of future scenarios. With that, normative scenario building becomes a quantitative process in which benefits, performance, and risks can be analysed and optimised according to different parameters. The second part of the thesis, and its third main original aspect, illustrates the framework in a specific case study of metro systems in megalopoleis. Models are used to identify the functional paradoxes that are used to develop a proposed concept that comprises three main operational foundations. Firstly, an operational strategy where autonomous vehicles stop in different patterns along the line to reduce access times without an impact on in-vehicle times. Secondly, stations are located off the main line to guarantee that all passengers can board their preferred services within minimum headways. Finally, the operational concept adopts autonomous vehicles that travel in platoons and are controlled by vehicle-to-vehicle communication algorithms similarly to automated highways. Results show that this type of solution can potentially improve door-to-door journey times in metro systems if practical barriers can be overcome. In theory, it can reduce the distance between stations to a minimum and thus reduce access time by 50%, while simultaneously increasing in-vehicle speeds by 45% and reduce door-to-door journey times by up to 31% compared to conventional operations. Moreover, capacity can also be increased between 20% and 40% compared to current systems. Therefore, this thesis proposes a series of heuristic steps rooted in normative scenarios to develop operational concepts which are not only innovative but also robust, in a quantitative and verifiable manner. Systems can be functionally modelled, allowing specific technical requirements and specifications to be met in the future. With that, the limitations of current capabilities are reversed from their original position of functional constraint, to a position of normative functional guidelines for development. By focusing on what tools to develop for an ideal system rather than a system that adapts to current tools, this research is a starting point to a new perspective on developing future urban systems

A hybrid Delphi-AHP multi-criteria analysis of Moving Block and Virtual Coupling railway signalling

The railway industry needs to investigate overall impacts of next generation signalling systems such as Moving Block (MB) and Virtual Coupling (VC) to identify development strategies to face the forecasted railway demand growth. To this aim an innovative multi-criteria analysis (MCA) framework is introduced to analyse and compare VC and MB in terms of relevant criteria including quantitative (e.g. costs, capacity, stability, energy) and qualitative ones (e.g. safety, regulatory approval). We use a hybrid Delphi-Analytic Hierarchic Process (AHP) technique to objectively select, combine and weight the different criteria to more reliable MCA outcomes. The analysis has been performed for different rail market segments including high-speed, mainline, regional, urban and freight corridors. The results show that there is a highly different technological maturity level between MB and VC given the larger number of vital issues not yet solved for VC. The MCA also indicates that VC could outperform MB for all market segments if it reaches a comparable maturity and safety level. The provided analysis can effectively support the railway industry in strategic investment planning of VC

Sensitivity enriched multi-criterion decision making process for novel railway switches and crossings - a case study

Background: Despite their important role in railway operations, switches and crossings (S&C) have changed little since their conception over a century ago. It stands now that the existing designs for S&C are reaching their maximum point of incremental performance improvement, and only a radical redesign can overcome the constraints that current designs are imposing on railway network capacity. This paper describes the process of producing novel designs for next generation switches and crossings, as part of the S-CODE project. Methods: Given the many aspects that govern a successful S&C design, it is critical to adopt multi criteria decision making (MCDM) processes to identify a specific solution for the next generation of switches and crossings. However, a common shortcoming of these methods is that their results can be heavily influenced by external factors, such as uncertainty in criterium weighting or bias of the evaluators, for example. This paper therefore proposes a process based on the Pugh Matrix method to reduce such biases by using sensitivity analysis to investigate them and improve the reliability of decision making. Results: In this paper, we analysed the influences of three different external factors, measuring the sensitivity of ranking due to (a) weightings, (b) organisational and (c) discipline bias. The order of preference of the results was disturbed only to a minimum while small influences of bias were detected. Conclusions: Through this case study, we believe that the paper demonstrates an effective case study for a quantitative process that can improve the reliability of decision making

The metro system of future megacities

The recent quick urbanisation process has led to a situation where metro systems are no longer able to offer the necessary speeds to cover the ever increasing distances travelled. This reinforces the vicious circle that promotes private mobility and threatens the sustainability of cities. Even though metro systems can achieve higher top speeds than permitted on roads, their main disadvantage lies in the coverage paradox: when stations are close together, the time to walk to stations is short but the speed in the metro is also reduced for stopping more times. Conversely, if stations are far apart for higher speeds on the line, the time to access stations is also increased. Consequently, a journey using the metro always takes more time than it would on private modes. Using a systems engineering process, this research proposes a novel operational model where autonomous vehicles stop in different patterns at stations along a line. These vehicles travel in convoys instead of trains and are controlled by vehicle-to-vehicle communication similarly to those developed for automated highways. Simulations show that this strategy can simultaneously reduce by half the time to access stations and increase by 130% the average speed on the line, thus shortening journey times by up to 45% compared to conventional operations. Moreover, capacity is also increased by 30% compared to the busiest lines in operation. In conclusion, the model can meet the speed requirements of megacities, while increasing the capacity of systems to cope with the demographic trends of the twenty-first century

Developing a New Technical Strategy for Rail Infrastructure in Low-Income Countries in Sub-Saharan Africa and South Asia

Low-income countries (LICs) in Sub-Saharan Africa and South Asia are investing in new railway lines to replace deteriorated infrastructure from the 19th and 20th century. These actions, despite financial and economic constraints, have been justified in common visions of continent-wide efficient networks to cope with the demands of growing populations. However, most of the recent rail infrastructure projects are driven by international suppliers’ preferences and financing rather than creating railways that match the requirements of interoperable regional networks. This paper therefore explores the current status of rail infrastructure in these LICs and the operational performance achieved to understand specific capability gaps in each regional network. Drawing from the experience of European countries in transforming regional future visions into applied research, a technical strategy for rail infrastructure in LICs is proposed. The strategy captures the key capabilities to be addressed in order to achieve future performance goals, while emphasizing the need for emerging technologies to be used in fit-for-purpose solutions. It is envisioned that the strategy will provide the basis for the development of continental technical strategy programs with specific technology roadmaps towards a common goal

A systems approach to developing a new metro for megalopoleis

The significant growth in the size of cities has led to an increase in distances travelled that emphasises the systemic shortcomings of metros. Metro systems are hindered by a paradox between the time to access stations and the average speed on the line, which prevents them from offering competitive door-to-door speeds within the natural time budgets of users. The authors present a novel methodology that combines the back-casting method with a systems engineering approach to develop a robust problem-solving process that can cope with the uncertainty of future scenarios. The approach has been used to develop a solution to the paradox, that is based on an operational strategy where autonomous vehicles stop in different patterns at stations along a line. It is proposed that vehicles will travel in platoons and be controlled by vehicle-to-vehicle communication algorithms similarly to those in automated highways. Simulations show that this strategy can increase the average speed on a line by 129%, reducing door-to-door journey times by up to 45%, compared to conventional operations. Moreover, capacity is increased by 30% within conventional platform lengths. In conclusion, this process can lead to solutions that accommodate future demands and change current trends into more desirable futures. </jats:p

Determining future high speed rail review topics through bibliometric analysis

As high speed rail (HSR) has proliferated globally, so has a related research field dedicated to exploring and addressing its unique issues. Yet, studies to understand and classify the HSR research domain are limited. This paper addresses the gap, using bibliometric analysis to identify future research areas and 20 candidate topics for literature review based on keyword analysis through VOSviewer. Article and review papers related to HSR published in the last 20 years (2003-2022) were retrieved from Scopus, and then analysed to determine the split in knowledge between languages, the collaboration between countries and institutions, highly productive and cited journals, and research topics which have and have not been reviewed. Approximately 30% of the search results were published exclusively in Chinese, highlighting the importance of extending the evaluation to cover both languages. This is a novel aspect of the work, which has enabled the recognition of potential knowledge gaps. It is recommended that future reviews incorporate works in both languages, possibly through international collaboration. Institutions in China and other countries that are strong collaborators have been identified, as well as relevant highly cited journals

Using Radical Innovation to Overcome Utility Trade-Offs in Urban Rail Systems in Megalopoleis

Urban mobility is increasingly becoming accepted as a basic human need, as socio-economic opportunities depend on the ability to reach places within an acceptable time. Conversely, the emergence of megalopoleis as dominant features of the global landscape has increased commuting effort to unprecedented levels, due to the ever expanding urban areas and the associated travel distances. This now poses a risk to the efficient accessibility of cities, but there is an assumption that the problem can be overcome by increasing the speed of transport systems. However, advocates of this approach overlook important utility trade-offs that arise from the conflict between greater vehicle speeds and the additional time required to access the services. In this paper, we investigate this approach and show that higher speeds in metro systems do not always result in faster travel in cities. We then propose a new approach to addressing the problem, which culminates in a solution that can overcome the current paradoxes and increase door-to-door speeds more effectively. The resulting operational concept optimizes speed and coverage in urban rail systems in megalopoleis, accommodating the longer trips within time budgets. We position this research as a starting point to a new perspective on developing complex urban systems in the future